IFNG and hereditary spastic paraplegia: Moreover, the results of enzyme-linked immunosorbent assay (ELISA) showed that the levels of the M1 (IFN-γ and IL-12) and M2 (TGF-β and IL-4) macrophage cytokines were markedly decreased and increased, respectively, in the RMDMs of HSP group compared with the control group (Figure 1(C–F)).